Updated from 9:30 a.m.Altria ( MO) shares fell Friday after Prudential downgraded the stock because of upcoming litigation likely to impact the company's Philip Morris unit. Altria was downgraded from overweight to neutral but the brokerage maintained its share price target at $54, citing an "unattractive risk/reward profile" in the next three to six months. Prudential's three-person analyst team said lawsuits from smoking victims on both the federal and state level could provide negative news flow that "may have a substantial impact on the valuation." In particular, Prudential referred to the possibility that Florida's Supreme Court could review a recent ruling by a lower court in favor of Altria and the Justice Department's case against the tobacco industry now scheduled to start in September. (Prudential's analysts do not own shares in Altria, but the broker has an investment banking relationship with the company.) Prudential also said it does not see the tobacco business improving quickly, although fundamentals are improving. Recently, Altria shares were off $1.55, or 2.7%, to $54.77.